In the past, a smooth surface of a stainless steel substrate is generally obtained by applying chemical force such as acid etching during a chemical mechanical polishing treatment, or by applying mechanical force with hard wear-resistant particles, such as alumina, silicon carbide, or silicon oxide, on the surface of the stainless steel. Besides, in US patent US20140127983 A1 and a publication document “Advances in the materials science and engineering synthesis and characterization of SiO2 nanoparticles and their efficacy in chemical mechanical polishing steel Substrate” disclosed by Kao et al., there is no disclosure of a polishing slurry being modulated with chemical formulations during the chemical mechanical polishing process.
In addition, in the existing prior art, most of the polishing slurries used for polishing the stainless steel substrate are adopted with acidic metal polishing liquids, which are usually unable to provide an excellent polishing performance on the stainless steel substrates.
However, in a fine polishing process for chemical mechanical polishing, in addition to using a fine polishing slurry to reach the surface finishing and to improve the surface flatness of the stainless steel substrate, some developing works such as removing and repairing scratches or other surface defects remaining from a rough polishing step are also required, so as to obtain a perfectly polished surface of the substrate.